On the interpretation of the racemic states of the B 2 phase of banana-shaped mesogens

We show that the racemic states of the B 2 phase of liquid crystals composed of banana-shaped molecules do not satisfy the Curie principle. Thus it is argued that these states cannot exist in bulk samples and the homochiral states constitute the only stable microscopic structures. A reinterpretation of the racemic states with the same macroscopic optical behaviour is proposed in terms of mixtures of the homochiral structures.     

Spectrum of a random Schrödinger difference operator

Translated from Matematicheskie Zametki, Vol. 50, No. 3, pp. 81–86, September, 1991.     

First measurement of the ϱ spectral function in nuclear collisions

The NA60 experiment at the CERN SPS has studied low-mass muon pairs in 158 A GeV In–In collisions. A strong excess of pairs is observed above the yield expected from neutral meson decays. The unprecedented sample size close to 400000 events and the good mass resolution of about 2% made it possible to isolate the excess by subtraction of the decay sources. The shape of the resulting mass spectrum shows some non-trivial centrality dependence, but is largely consistent with a dominant contribution from π⁺π^-→ϱ→μ⁺μ^- annihilation. The associated ϱ spectral function exhibits considerable broadening, but essentially no shift in mass. The p_T-differential mass spectra show the excess to be much stronger at low p_T than at high p_T. The results are compared to theoretical model predictions; they tend to rule out models linking hadron masses directly to the chiral condensate. PACS 25.75.-q; 12.38.Mh; 13.85.Qk     

Copolymers of acrylic acid with urea

Composition and rheological characteristics of aqueous solutions of acrylic acid/urea copolymers were studied, including the composition dependences of the equivalent conductivity and viscosity.     

三级近似束流光学计算程序

为了精确计算束流在离子光学系统中的传输,用Visual FORTRAN 6.5语言编写了一个计算程序,长约13000行. 此程序可以计算由三圆筒单透镜、三膜片单透镜、双元筒透镜、均匀场静电加速管、磁四极透镜、六极磁铁、静电四极透镜、偏转磁铁、螺线管透镜、ExB~正交电磁场分析器、静电偏转器、漂浮管、QWR(Quarter Wave Resonators)和SLR(Split Loop Resonators)射频加速元件等元件任意组成的离子光学系统. 粒子轨迹的计算可精确到三级近似. 粒子的分布类型也可以有多种选择. 程序具有最优化计算功能,即可以自动调整元件的参数,以实现所需要的光学条件. 各元件之后的横向和纵向相图以及系统的束流包络线以图形方式显示在屏幕上.     

The simulation of molecular and organic devices: a critical review and look at future developments

Molecular devices have lately attracted increased attention due to some appealing features such as their low production cost, flexibility in the substrate choice, possibility of large area deployment, and possibly higher integration capabilities. Starting from a series of results obtained from our groups, we critically review the state-of-the-art in the field of simulation of organic and molecular systems, by analyzing and comparing existing approaches, and looking at the open problems and possible solutions and future developments. PACS 72.80.Le     

Mechanical and thermal properties of cryogels and foamed cryogels produced from aqueous solutions of poly(vinyl alcohol)

The effect of sodium chloride and technical-grade carbon (carbon black) on the mechanical and thermal properties of cryogels and foamed cryogels produced from homogeneous and heterogeneous (foamed) solutions of poly(vinyl alcohol) was studied.